Interlocking system for railroads



Jan. 7, 1936. s. N. WIGHT Re; 19,814

INTERLOCKING SYSTEM FOR RAILROADS Original Filed July 18, 1929 ATTORNEY Reissued Jan. 7, 1936 UNITED STATES PATENT OFFICE INTERLOCKING SYSTEM FOR RAILROADS Sedgwick N. Wight, Rochester, N. Y., assignor to General Railway Signal Company, Rochester,

8 Claims.

This invention relates to interlocking systems, and more particularly to a novel interlocking system in which all of the interlocking is carried on directly between traffic controlling devices rather than between levers controlling such trafflc controlling devices.

As understood by those skilled in the art of interlocking practice, it is essential that no trafflc controlling device should be permitted to assume a particular indicating or control condition unless all conflictable traflic controlling devices are in a non-conflicting condition. In mechanical interlocking plants it is found expedient to have the interlocking mechanism associated with the levers, this for mechanical and structural reasons. During the evolution of interlocking practice this theory of interlocking levers mechanically has been carried on to interlocking plants employing electrically controlled traflic controlling devices.

In accordance with the present invention it is proposed to leave the control levers free for movement in any direction at all times, and to so interlock the circuits controlled by these levers,

" through contacts controlled by the various trafflc controlling devices, that it is impossible to supply clearing or operating energy to any particular traflic controlling device unless all of the conflictable traflic controlling devices have been operated to their non-conflicting positions or conditions.

Another object of the present invention resides in the provision of means for indicating in the tower if a particular trafiic controlling device cannot be operated by reason of the fact that there is a conflictable traflic controlling device in its conflicting position or condition.

Other objects, purposes and characteristic features of the invention will in part be described hereinafter and in part be obvious from the accompanying drawing.

In describing the invention in detail referenc will be made to the accompanying drawing which conventionally shows the control circuits and devices of a particular way station together with a lever and indicating apparatus located in the dispatchers ofiice.

Referring to the drawing the main track of a railway system has been shown by track rails I divided into track sections by insulating joints 2,

of which the track sections A, B and C only have been shown. From this main track diverge the routes D and E, comprising rails 3 and 4 respectively. Each of these track sections is provided with the usual track circuit, of which the track section A has a track circuit including the battery 5 and the track relay T, the track circuit of section B includes the track relay T and the battery 6, the track section C has a track circuit including the battery I and the track relay '1', and the track circuit of section E contains the track relay T and the track battery 8.

The diverging route E is connected to the main track through the medium of the track switch S and the diverging route D is connected to the main track through the medium of the track switch S At the entrance to the diverging route E is located a main signal ME and a take-siding signal DE, whereas at the entrance to the diverging route D there is located a main west-bound signal MW. The switches S and S are provided with the usual switch box contacts, which contacts are included in the interlocking circuits more clearly described in connection with the operation of the system. Also, if desired, these switches S and S may be operated by switch machines controlled by control relays and indicating track circuit occupancy in a manner as shown in the application of F. L. Dodgson, Ser. No. 187,508, filed April 29, 1927.

In the interlocking tower, the entire interlocking plant or plants are preferably reproduced in miniature, and for convenience only that part of the railway system shown in the drawing has been shown reproduced in miniature in the interlocking tower. This miniature track layout shows the diverging route e and the diverging route at as well as the miniature wayside signals me, ale and mw. In the particular arrangement shown, the main signal ME is controlled by lever L and the take-siding signal DE is controlled by the lever L It is believed that the novel features and operating characteristics of the system will be best understood by considering the operation of the system.

Operation Although the switches S and S may be either hand-operated from a local switch stand, or operated from the interlocking tower either mechanically or electrically, it is for convenience assumed that these track switches are operated from the dispatchers oflice by mechanical means such as pipe lines or cables.

Let us assume that both of these track switches S and S assume the main track position. Let us further assume that the operator wishes to clear the main signal ME. In order to do so the operator will operate the lever L to its dotted proceed position, thereby completing the following circuit:beginning at the tower battery Ill, wire ll, lever L wires I2 and I3, winding of the indicating relay IR, line wire I4, contact I5 on the west-bound signal MW, wire I6, front contact I! of the track relay T wire I8, switch box contact I9, wire 20, front contact 2| of the track relay T wire 22, winding of the control relay IZ, wire 23, switch box contact 24, wire 25, front contact 26 of the track relay T, wire 21, common return wire C to the negative terminal of battery in. Under this assumed condition of the various track relays and switch box contacts in the circuit just traced, the control relay IZ. will assume its energized position. With the control relay IZ assuming its energized position, the main signal ME is free to assume its proceed position, providing traffic conditions in advance thereof are clear. In this connection it may be pointed out that the circuit just traced'in itself checks trafllc conditions to the next opposing signal in advance, but in some cases the signal ME, may if desired, be prevented from assuming its proceed pw tion because there is another train in the next section ahead of the track section 0 by the inclusion'of suitable signal blade or line relay contacts inlsaid circuit. With, the circuit through the control relay IZ closed, this on the assumption that there is no conflicting route set up, the indicating relay JR will assume its energized position, thereby. closing an energizing circuit through the indicating lamp me, which circuit includes the front contact .30 of the indicating relay IR.

Should now an east-bound train accept the signal ME. in its proceed position, and should it move into the track section A the track relay T would assume its de-energized position, thereby breaking the energizing circuit for the relay IZ atthe contact 26' of the track relay T, and in turn effect deenergization of the indicating relay IR and extinguishment of the indicating lamp me. Similarly, occupancy of the track sections Band C will effect extinguishment of the indicating lamp me through the medium of the opening of contacts 2| and ll of the relaysT and T. The operator will thus be, informed of the entrance of the train into the section of track A, B, and C.

Let us now assume that the operator returns the lever L back to its normal position, and through the medium of a large lever, (not shown) which actsthrough mechanical means to operate the track switch S operates the switch S to the take-siding position. Under this condition the signal ME cannot be cleared because the switch box contact 24 now assumes the dotted position, and the circuit for the control relay lZ for this reason cannot be completed.

Let us now assume that the operator moves the lever-L to its dotted position. Under this condition the following circuit is closed. provided the track section E and the fouling track circuit A is not occupied by another train:beginning at the battery liLwires H and 35, lever L ,'wires 36 and 31, winding of the indicating relay 2R, wire 38,

frontcontact 39 of the track relay T wire 46, winding of the relay 2Z, wire 4|, switch box contact 24, wire 25, front contact 26 of the track relay'T,,wire 21, and common return wire 0 to the negative terminal of battery I6. With the controlrelay ZZ assumingits energized position, due to completion of this circuit the dwarf signal DE will assume the proceed position through the medium of the front contact 45 of the control relay 2Z.' It is thus seen that the dwarf signal DE cannot assume its proceed position unless. the

track switch S is in the take-siding position and the track relays T and I are in their energized position.

Should either the track switch E or the fouling track circuit A be occupied at the time that the operator moves his lever L he will be informed of that fact by reason of failure of the indicating lamp dc to be illuminated, it being understood that with energizing current for the control relay 2Z actually flowing through indicating relay 2R connected inseries therewith, the relay 2R will also assume its energized position, and will illuminate the indicating lamp de through a circuit including the front contact 46 of the indicating relay 2R. Although the track switches S and S have been assumed to be operable from the tower mechanically, these track switches may be operated by switch machines protected against dangerous, operation by approach locking circuits and detector locking circuits, all in a manner as describedin-detail in. my prior application Ser. No. 120,423, filed July 3,, 1926, to which reference may be had, if desired.

Applicant has thus provided an interlocking, system in which all of the features of interlock ing are located locally with respect to thetraflic controlling devices, and in which. the control leversare free-to be moved at any time, and in any manner, the entire protection against operat ing traflic controlling devices to positions conflicting with: routes then set up being taken; care ofby local interlocking circuits including contacts of conflictable tramc controlling devices. Further, the system proposedindicatestothe operator that a certain route cannot be set up in the event that such is the case, by failure of the indie eating lampionthe miniature tracklayoutto-be illuminatedlin response to movement ofthe, core responding lever. Also, thesev sameindicatine lamps inform theoperator of the passage-of:.za train over the route set up, in that they indicate when the signal. at the entrance to such route assumes its danger position in response ,to, the movement of trains into such route.

Having thus shown and described one rather specific embodiment of the present invention,- itis desired tobe understood that the particular em--. bodiment illustrated has been shown for the pun pose of exemplifying the invention and facilitating description thereof, and has not been selected for the purpose of showing the exact construction and circuit arrangement preferably employed in practicing the same, and that various changes, modifications and additions may be made to adapt the invention to any particular track layout to which the invention is to be applied, all without departing from the spirit or scope of the invention, or the idea of means underlying the same, except as demanded by the scope of the following claims.

What I claim as new is: p

1. In an interlocking system, the combination with a. plurality of levers in an interlocking tower free to be moved to any position at any time, a traffic controlling device for each lever controlled by such lever and located at a distant way station, a control relay associated .with each tramc controlling device for controlling the operative condition of such device, a circuit'controlled by one of said levers for a particular control relay including contacts mechanically operated by other and conflicting traflic controlling devices closed only when such conflicting tramccontroh ling devices are in their non-conflicting positions.

and indicating means in said interlocking tower included in series in said circuit at a point in said tower for indicating the continuity of said circuit through said particular control relay.

2. In an interlocking system, the combination with a. plurality of levers in an interlocking tower free to be moved to any position at any time, a trafiic controlling device for each lever controlled by such lever and located at a distant way station, a control relay associated with each tramc controlling device for controlling the operative condition of such device, a circuit controlled by one of said levers for a particular control relay including contacts mechanically operated by other and conflicting traflic controlling devices closed only when such conflicting trai'lic controlling devices are in their non-conflicting positions, an indicating relay in said interlocking tower included in series in said circuit at a point in said tower and assuming its attracted position when said circuit through said control relay is energized, and an indicator controlled by said indicating relay and rendered active when said indicating relay assumes its attracted position.

3. In an interlocking system, the combination with a plurality of levers in an interlocking tower free to be moved to any position at any time, a traflic controlling device for each lever controlled by such lever and located at a distant way station, a circuit controlled by one of said levers for controlling a particular trafiic controlling device including contacts controlled by other and conflicting trafiic controlling devices closed only when such other conflicting traffic controlling devices are in their non-conflicting positions, and means included in series in said circuit at a point in said interlocking tower for indicating at said tower the flow of current through said particular traiilc controlling device and thereby indicating if any of said conflicting traflic controlling devices are in a conflicting position.

4. In an interlocking system, the combination with a plurality of levers in an interlocking tower free to be moved to any position at any time, a traflic controlling device for each lever controlled by such lever and located at a distant way station, a control relay associated with each trafiic controlling device for controlling the operative condition of such device, a circuit controlled by one of said levers for controlling a particular control relay including contacts associated with other and conflicting traffic controlling devices closed only when such conflicting traflic controlling devices are in their non-conflicting positions, and indicating means in said interlocking tower and included in series in said circuit at a point in said tower for indicating the continuity of said circuit through said indicating means and through said particular trafiic controlling device.

5. In an interlocking system, the combination with a plurality of levers in an interlocking tower tree to be moved to any position at any time, a

- trafl'ic controlling device for each lever controlled by such lever and located at a distant way station, a control relay associated with each traflic controlling device for controlling the operative condition of such device, a circuit controlled by one of said levers for a particular control relay including contacts associated with other and conflicting traflic controlling devices closed only when such conflicting traflic controlling devices 5 are in their non-conflicting positions, an indicating relay in said interlocking tower and included in series in said circuit at a point in said tower and assuming its attracted position when said circuit is energized, and an indicator in said interlocking tower and controlled by said indicating relay and rendered active when said indicating relay assumes its attracted position to thereby indicate the condition of one traflic controlling device over the same circuit used for controlling another trafiic controlling device.

6. In an interlocking system, the combination with a plurality of levers in an interlocking tower free to be moved to any position at any time, a wayside signal for a particular lever and located at a distant point, a track switch and an opposing signal ahead of said signal, a circuit controlled by said particular lever for controlling said first mentioned signal and including contacts controlled respectively in accordance with the position of said track switch and the position of said another signal in advance, said contacts being closed only if said another signal in advance is at stop and said track switch is in a nonconflicting position, and indicating means in said 80 interlocking tower included in series in said circuit at a point in said tower for indicating if said contacts are closed.

7. In an interlocking system, the combination with a plurality of levers in an interlocking office 85 each free to be moved to any position at any time, a wayside signal for governing trafllc in a particular direction over a stretch of track, another wayside signal for governing traflic in the opposite direction over said stretch, a circuit for controlling one of said signals including a contact of one of said control levers and a contact closed only when the other signal is in its stop condition, and indicating means in said interlocking tower and included in series in said circuit at a point in said tower for indicating the continuity of said circuit and in turn the indicating condition of said other wayside signal.

8. In an interlocking system, the combination with a plurality of levers in an interlocking ofilce each free to be moved to any position at any time, a. wayside signal for governing traflic in a particular direction over a stretch of track, another wayside signal for governing traflic in the opposite direction over said stretch, a circuit controlled by one of said levers and for controlling one of said signals and including contacts closed only if said stretch of track is unoccupied and said other signal is in its stop condition, and indicating means in said interlocking tower and 0 included in series in said circuit at a point in said tower for indicating the continuity of said circuit and in turn the occupancy of said stretch of track if said other signal is in the stop condition. as

SEDGWICK N. WIGHT. 

